Do Deportations Lower Crime? Not According to the Data

A new study casts doubt on the effectiveness of a program that encourages local police cooperation with federal immigration enforcement.

In one of Donald J. Trump's earliest moves as president, days after his inauguration, he revived the deportation program known as Secure Communities.

Proponents argue that it helps prevent crime and also increases the police’s ability to solve crime through collaboration with federal immigration enforcement. But a new study from the University of California, Davis, has cast doubt on the ability of Secure Communities to do either.

The program, involving cooperation between Immigration and Customs Enforcement (ICE) and local police departments, began under George W. Bush in 2008. President Obama expanded it drastically during his first term but in 2014 discontinued it.

Jurisdictions across the country rolled out the program in varying ways. Some places had few or no deportations; in others, deportations approached or even exceeded half a percent of the local population. Some introduced the program as early as 2008, while others didn’t begin until 2013.

The nationwide examination of over a thousand local areas before and after they adopted Secure Communities found a consistent outcome: Places that deported the most appeared no safer than those that deported the fewest.

Deportations and crime: no sign of a link

Areas that implemented the Secure Communities program most aggressively deported half a percent of their working age population or more. Crime outcomes in these areas were similar to those in areas that deported only a few people, or no one.

Each dot represents a Public Use Microdata Area (PUMA),
before and after implementation of Secure Communities.

Crime has been declining in many areas across the country for decades, and it continued to do so under Secure Communities. If deportation were an effective crime-prevention method, places that deported the most would display larger decreases in crime than other areas. No trends like that were observed.

But crime data is notoriously noisy, and dependent on a complex range of factors, potentially masking real trends. To counteract some of these possible confounding factors, the authors of the paper took advantage of the program’s staggered rollout to produce data with widely varying conditions.
This natural experiment, in conjunction with models controlling for a variety of demographic and socioeconomic factors, was used to help isolate the potential effect of deportation policy from overall factors and trends in the country. It found no link between higher deportation rates and lower crime.

Nashville introduced one of the most aggressive versions of Secure Communities, starting gradually in 2010. By the program’s end in 2014, more than 1,600 people in the city had been deported—almost half a percent of its working age population.

Since Trump restarted the program in 2017, the situation for Nashville’s undocumented immigrants has only gotten worse, said Mary Kathryn Harcombe, lawyer and legal director at the Tennessee Immigrant and Refugee Rights Coalition. She recalled the effect on local law enforcement of Trump’s early policy memos shifting deportation priorities away from those convicted of serious crimes.

“There was no prioritizing,” she said. “Everybody is fair game. The use of the criminal justice system was no longer based on the concept of somebody who has committed a crime is more dangerous—it was simply a dragnet system.”

Blurring enforcement priorities heightens the risk of deportation for those with minor convictions, including for misdemeanors like traffic offenses; for violations related only to immigration status, like an overstayed visa; and for those charged with a crime but not convicted. Before Secure Communities was discontinued, a tenth of a percent of Nashville’s working age population had been deported as a result of minor violations—a rate higher than that in 97 percent of areas nationwide.

The immigration debate in the Nashville area has drawn national attention. In 2008, a routine traffic stop led to the arrest of Juana Villegas, who was nine months pregnant and turned out to be driving without a license and to have previously been deported. Detained for almost a week, she gave birth in custody, cuffed to a hospital bed much of the time.

This summer, neighbors and activists formed a human chain around a man and his 12-year-old son to keep away ICE officers seeking to apprehend them in their vehicle. More recently, an ICE agent opened fire after approaching a truck in a grocery store parking lot. The driver, who an ICE spokesman said had been previously deported, sustained two gunshot wounds as he tried to drive away and later turned himself in to authorities. The FBI, which is investigating, said it had not yet arrested or charged the man.

The Nashville-Davidson County Sheriff’s Office expressed support for cooperation between local law enforcement and federal immigration authorities. “We believe if someone is criminally active in the community and also wanted by ICE, it is responsible to cooperate,” Karla West, the office’s chief of staff, said via email. “We will continue to bring a balanced, responsible approach to this subject regardless of the political environment.”

Throughout, a coalition of city policy makers, lawyers and immigrant advocates have battled to disentangle the city’s government agencies from ICE operations. They’ve called on the Nashville sheriff to stop renting bed space for ICE detention. They’ve also asked local agencies to limit their employees from sharing information about custody, release dates or court appearances—and to stop complying with ICE detainer requests that lack a judicial warrant.

In response, Tennessee passed a bill withholding funding from any city that limits cooperation with ICE. “The state law appears to be specifically aimed at Nashville,” Harcombe said. “We are a blue island in a red sea.”

Many Americans say illegal immigration is itself a crime (it is a civil violation or a misdemeanor, depending on if a person overstayed a visa or crossed the border without authorization). And some say undocumented immigrants are unlikely to report crimes commited against them by other undocumented immigrants.

The paper also evaluated claims that Secure Communities could help the police solve crimes more effectively through information sharing. Comparing clearance rates—the rates at which reported crimes are marked as resolved by the police—again showed no effect. Crimes were solved at similar rates regardless of the aggressiveness of deportations in an area.

As arguments rage in cities across the country over the role of local police in Trump’s immigration operations, the administration has escalated deportations in recent months. The justification often used is to keep communities safe.

Researchers said an evaluation of the data that already exists was the best way to resolve this question and guide the future of deportation policy. Giovanni Peri, a professor of economics at U.C. Davis, authored the study with Annie Laurie Hines, a graduate student in the U.C. Davis economics department, while both were research fellows at TRAC. “The motivation was, let’s try to learn from the past,” he said.

Anna Flagg
is The Marshall Project's senior data reporter, covering criminal justice topics including immigration, crime, race, policing and incarceration. Her work has been recognized by the Global Editors Network’s Data Journalism Awards, the Society of News Design and the Information is Beautiful Awards, and she was a finalist for a 2019 Deadline Club Award.